Microstructure- and Interface-Modified Ni-Rich Cathode for High-Energy-Density All-Solid-State Lithium Batteries
Un‐Hyuck Kim, Tae‐Yeon Yu, Jin‐Wook Lee, Han Uk Lee, Ilias Belharouak, Chong Seung Yoon, Yang‐Kook Sun
Abstract
Electric vehicles powered by Li-ion batteries pose a potential safety risk because the flammable liquid electrolytes can, under certain conditions, cause explosions. All-solid-state batteries (ASSBs) are safe alternative battery technologies. However, realizing high-energy-density ASSBs by employing Ni-rich layered cathodes is difficult because of the detrimental volume contraction near charge end. This study shows that the simultaneous B doping and coating of a Ni-rich Li[Ni 0.9 Co 0.05 Mn 0.05 ]O 2 cathode, which modifies the cathode microstructure and cathode–solid electrolyte interface, respectively, afford an ASSB that cycles stably for 300 cycles with minimal capacity fading. An ASSB featuring the B-doped, B-coated Li[Ni 0.9 Co 0.05 Mn 0.05 ]O 2 cathode demonstrates a discharge capacity of 214 mAh g –1, which represents one of the highest discharge capacities achieved by an ASSB; moreover, the ASSB retains 91% of its initial capacity after 300 cycles and easily outperforms previously reported ASSBs in terms of energy density without compromising cycling stability.